The song is called "U Smile" by Justin Beiber.
Smile is by Uncle Kracker
Rod sings SMILE in the key of A
Uncle cracker
Alison Krauss- The Smile On Your Face
Smile Inside by Tim Myers & Ane Trolle
Johny Mathis i believe
nat wolff
nat wolff
While this is a line common to several songs, the one most frequently heard at this time would likely be "When You Smile At Me," by Amie Comeaux.
SMILE EMPTY SOUL - Bottom Of A Bottle
Barry Manilow sings it. http://en.wikipedia.org/wiki/Can%27t_Smile_Without_You
If you mean the one Michael Jackson liked you mean Smile by Charlie Chaplin